The equations for linear motion I've memorized are: 1.) v = u + at 2.) v^2 = u^2 + 2as 3.) s = ut + 1/2(at^2) v = final velocity, u = initial velocity, a = acceleration, t = time, s = displacement In an example my physics teacher uses the equation x = x0 + (v^2-u^2)/2a I'm assuming he derived that from the second equation I listed but I can't figure out why (v^2-u^2) is divided by 2a. When I rearrange that equation I get s = v^2 - y^2 - 2a Am I just using incorrect algebra or is that a different equation altogether?